What happened
The aircraft was observed entering a valley characterized by mountains on both sides. While the pilot was maneuvering the airplane to the left to reverse direction, it collided with terrain.
Witnesses reported that the plane's engine sounded normal and that the weather was good with clear skies, unlimited visibility, and light wind. A pilot who flew over the accident site minutes after the mishap reported the area was devoid of turbulence. This was a Part 135, on-demand, lodge/hunting guide operation.
The investigation
No mechanical examination details were provided in the source material.
Findings
The aircraft collided with terrain during maneuvering. Witnesses reported normal engine operation and good weather conditions at the time of the mishap.